System and method for conveying end-to-end call status

ABSTRACT

A system that incorporates teachings of the present disclosure may include, for example, a Unified Messaging System having a controller element to submit to a Calling Card Server (CCS) over a primary call leg a Session Initiation Protocol (SIP) SUBSCRIBE message requesting outdial event notification for a call placed on a secondary call leg responsive to a reply of a voicemail message, and receive over the primary call leg a SIP NOTIFY message from the CCS indicating outdial events associated with placing the call over the secondary call leg. Additional embodiments are disclosed.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to communication techniques andmore specifically to a system and method for conveying end-to-end callstatus.

BACKGROUND

In a Voice over Internet Protocol (VoIP) network, establishment of anend-to-end call may involve multiple communication legs each providingits own signaling mechanisms. For example, when a Unified MessagingSystem (UMS) operating in an IP Multimedia Subsystem (IMS) networkreceives a request from a subscriber to browse voicemails, a commonoption of the UMS is to provide the subscriber an auto-dial feature torespond to the voicemail message without terminating the call. When thecall is outside of the Local Access and Transport Area (LATA) of theUMS, the UMS (due to regulatory reasons) has to re-direct the call to anintermediate system such as a Calling Card Server (CCS) to place thecall.

When the CCS places the call to the Called Endpoint, it will typicallyreceive call progress tones via signaling messages. The CCS must thenconvert those call progress tones into in-band tones for the CallingEndpoint. The UMS under these circumstances does not know whether theCalled Endpoint is ringing or a busy signal is being transmitted. Thissituation can limit the UMS from providing the calling party additionalsupplemental communication features during the call set-up process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an exemplary embodiment of a communication system;

FIG. 2 depicts an exemplary diagram for conveying call status in thecommunication system;

FIG. 3 depicts a flowchart illustrating an exemplary method operating inportions of the communication system;

FIG. 4 depicts an exemplary flow diagram to illustrate the method ofFIG. 3; and

FIG. 5 depicts an exemplary diagrammatic representation of a machine inthe form of a computer system within which a set of instructions, whenexecuted, may cause the machine to perform any plurality of themethodologies disclosed herein.

DETAILED DESCRIPTION

In one embodiment of the present disclosure, a computer-readable storagemedium operating in a Calling Card Server (CCS) can have computerinstructions for receiving from a Unified Messaging System (UMS) aSession Initiation Protocol (SIP) SUBSCRIBE message over a primary callleg requesting outdial event notification on a secondary call leg,placing a call on the secondary call leg responsive to receiving on theprimary call leg outdial information from the UMS, and submitting a SIPNOTIFY message to the UMS that indicates outdial events associated withcall status of the call on the secondary call leg.

In one embodiment of the present disclosure, a UMS can have a controllerelement to submit to a CCS over a primary call leg a SIP SUBSCRIBEmessage requesting outdial event notification for a call placed on asecondary call leg responsive to a reply of a voicemail message, andreceive over the primary call leg a SIP NOTIFY message from the CCSindicating outdial events associated with placing the call over thesecondary call leg.

In one embodiment of the present disclosure, a CCS can have a controllerto transmit a SIP NOTIFY message to a UMS over a primary call leg. TheSIP NOTIFY message can include call status associated with a secondarycall leg.

FIG. 1 depicts an exemplary communication system 100. The communication100 can comprise a Home Subscriber Server (HSS) 140, a tElephone NUmberMapping (ENUM) server 130, and common network elements of an IPMultimedia Subsystem (IMS) network 150. The IMS network 150 can becoupled to IMS communication devices such as an IMS -compliant phone111, or an IMS-compliant Unified Messaging System (UMS) 160 thatprovides unified messaging services such as voicemail, email, fax, andso on to subscribers of the IMS network 150.

The UMS 160 can comprise a unified messaging application server 162 thatutilizes common computing technologies to manage operations of one ormore media servers 164. The media server 164 can be used as anoff-the-shelf server (e.g., a Linux or Unix server) that performs mediaprocessing functions on media streams received from the IMS network 150that may require the resources of digital signal processors (DSPs) forencoding and decoding the media. The UMS can call on the media server164 to perform signal detection, such as Dual Tone Multi-Frequency(DTMF) signal processing, among other things, if necessary.

The UMS 160 can include an IMS compliant voicemail (VM) system 190. TheVM system 190 can include an interactive voice response system (IVR) forinteracting with the calling and called parties utilizing voice andkeyed input signals (e.g., DTMF tones), and for processing callbackmessages supplied by the calling party according to a call flow design.

A Calling Card System (CCS) 180 can be communicatively coupled to theUMS 160 by way of the IMS network 150. The CCS 180 may or may not be IMScompliant, though it can perform SIP messaging operations. The CCS 180can also include an Interactive Voice Response (IVR) system, or othersuitable interface systems. The CCS 180 can include technology forprocessing calling card information to help a user place a call, forexample via DTMF dialing, voice recognition, or other form of automata.The CCS 180 and the VM 190 can be provisioned to interact cooperativelyto support services of the UMS 160.

Communications within the communication system 100 can conform to anynumber of signaling protocols such as a session initiation protocol(SIP), or a video communications protocol such as H.323 which combinesvideo and voice over a packet-switched network, as well as cryptographicprotocols, such as transport layer security (TLS) or secure socketslayer (SSL), to provide secure communications for data transfers.

The MGCF 170 can conform to a media gateway control protocol (MGCP) alsoknown as H.248 defined by work groups in the Internet Engineering TaskForce (IETF). This protocol can handle signaling and session managementneeded during a multimedia conference. The protocol defines a means ofcommunication that converts data from the format required for acircuit-switched network to that required for a packet-switched network.For example, the MGCF 170 converts PSTN signals to IMS compliant signalsand vice-versa by common transcoding techniques. MGCP can therefore beused to set up, maintain, and terminate calls between multiple disparatenetwork elements of the communication system 100. For example, PSTNphones such as reference 172 can be accessed by the IMS network 150 byway of MGCF 170 coupled to the PSTN network 175 through for example oneor more ISDN User Part (ISUP) trunks.

To establish a communication session between devices, the IMS network150 can utilize an originating Serving Call Session Control Function(S-CSCF) 106. The originating S-CSCF 106 can submit queries to the ENUMserver 130 to translate an E.164 telephone number to a SIP UniformResource Identifier (URI) if the targeted communication device is IMScompliant. If the targeted communication device is a PSTN device such asreference 172, the ENUM server 130 will respond with an unsuccessfuladdress resolution and the originating S-CSCF 106 will forward the callto the MGCF 170 which connects the call through the PSTN network 175using common signaling means such as SS7.

In the case where the ENUM server 130 returns a SIP URI, the SIP URI isused by an Interrogating CSCF (I-CSCF) 107 to submit a query to the HSS140 to identify a terminating S-CSCF 114 associated with a targeted IMScommunication device such as IMS CD 111. Once identified, the I-CSCF 107can submit the SIP INVITE message to the terminating S-CSCF 114 whichthen identifies a terminating P-CSCF 116 associated with the targetedcommunication device. The P-CSCF 116 can then signal the communicationdevice to establish communications. When the targeted IMS communicationdevice is the UMS 160, the HSS 140 can identify a session bordercontroller (not shown) associated with the UMS. The I-CSCF 107 will thenestablish communications with the UMS 160 by way of the session bordercontroller. The aforementioned process can be symmetrical. Accordingly,the terms “originating” and “terminating” in FIG. 1 can be interchanged.

In addition to the network elements shown for the IMS network 150, therecan be a number of application servers 110 which can provide a varietyof services to IMS subscribers. For example, the application server 110can be used to perform originating treatment functions on the callingparty number received by the S-CSCF 106 in the SIP INVITE message.Originating treatment functions can include determining whether thecalling party number has international calling services, and/or isrequesting special telephony features (e.g., *72 forward calls, *73cancel call forwarding, etc.).

Although not shown, a cellular network can be communicatively coupled tothe PSTN network 175 to expand the reach of the IMS network 150 toportable communication devices operating according to a number ofwireless access technologies such as GSM-GPRS, EDGE, CDMA-IX, UMTS,WiMAX, UWB, software defined radio (SDR), and so on.

FIG. 2 depicts an exemplary illustration for end-to-end signaling in thecommunication system 100 between a calling party 101, the UMS 160, theCCS 180 and a called party end point 250. The primary leg 210establishing communications between the UMS 160 and the CCS 180 can beSIP enabled 211, while a secondary leg 220 establishing communicationsbetween the CCS and the called party 250 can be SIP or ISUP enabled 221.

FIG. 2 depicts an exemplary method 300 operating in portions of thecommunication system 100. When describing method 300, references shouldbe made to FIGS. 1, 2 and 4, although it is understood that method 300can be implemented in other suitable embodiments. It should also benoted that method 300 can include more or less steps and is not limitedto the order of steps shown.

With this in mind, method 300 can begin with step 302 in which a callingparty 101 calls the UMS 160 to retrieve voice mail messages. Whilebrowsing voice mail messages, the UMS 160 can present the calling party101 with an option to auto-dial in step 304 party 250 that left thevoice message. The UMS 160 can identify the party 250 leaving the voicemail via caller identification (e.g., caller ID) retrieved by the UMSfrom signaling information. The calling party 101 can also provide theUMS 160 a phone number of the party 250 who left the voice mail message.

In yet another embodiment, the UMS 160 can select a call back number ofparty 250 from presence information retrieved by common means from apresence server which party 250 is subscribed to. In this latterembodiment, the UMS 160 can use identification information supplied inthe voicemail message (e.g., caller ID) to identify the presence serverof party 250 from for example a profile held by the UMS, and determinefrom the presence information retrieved from the presence server whetherthe caller ID is still the best way to reach party 250. If it is not,the UMS 160 can replace the caller ID with another communicationidentifier retrieved from the presence information to contact party 250.

If the calling party 101 does not accept auto-dial at step 306, the UMS160 can continue to present calling options or end the call as directedby the calling party. If the calling party 101 at step 306 acceptsauto-dial, the UMS 160 proceeds to step 307 where it determines if thecaller ID or callback number results in an inter or intra Local Accessand Transport Area (LATA) call. If it is an intra-LATA call, then theUMS 160 processes the call within its LATA over the IMS network 150 bycommon means. If the call is an inter-LATA call (i.e., between LATAs),the UMS proceeds to step 310 where it transmits a SIP INVITE message toestablish communications with the CCS 180 over a primary call leg andtransmits a SIP SUBSCRIBE message to the CCS to request outdial eventnotification (see FIG. 2 and 411, 416 of FIG. 4).

The SIP SUBSCRIBE message can indicate that the calling party 101 wishesto receive information about the status of outdial events associatedwith a call placed by the CCS 180 to party 250. For example, the outdialevent can identify call set-up, dial-tone, ringing, busy, connect,off-hook, alert, or other suitable call status indicators. To establisha call with party 250 (referred herein as the called party 250) whichleft the voice mail message, the UMS 160 can submit in step 312 to theCCS 180 a calling card number and destination number of the called party250. This information can be conveyed by the UMS 160 to the CCS 180 withDTMF signals (see 420, FIG. 4). The destination number can be suppliedas an E. 164 telephone number, a SIP URI, or another suitablecommunication identifier. The CCS 180 can then use the destinationnumber to place in step 314 the outdial call as a SIP INVITE messagedirected to the called party 250 over a secondary call leg (see 421,FIG. 4). It should be noted that the called party 250 in the presentillustration can be an IMS-compliant device 111 or PSTN device 172 (seeFIG. 1).

At step 316, the CCS 180 can convey to the UMS 160 via SIP NOTIFYmessages call status received by the CCS on the secondary call leg. TheCCS 180 can supply the UMS 160 with the SIP NOTIFY message which caninclude SIP provisional and/or final signaling messages such as 180RINGING, 200 OK, or otherwise as defined by the Internet EngineeringTask Force (WETF) in Request For Comments (RFC) 3261. For example, asshown in FIG. 4, the CCS 180 can receive 180 ringing messages (see 422)from the called endpoint 250 which it can convey to the UMS as SIPNOTIFY (ringing) messages (see 423). The UMS 160 at step 318 can utilizethe signaling information supplied in the SIP NOTIFY message toimplement desired application logic.

For example, if the UMS 160 has only a caller ID or a single callbacknumber to reach the called party 250, the UMS can proceed to step 322where it conveys the signaling information it receives from the CCS 180over SIP NOTIFY messages to the calling party's IMS CD (or PSTN CD). Inthis scenario, if the called party answers the call in step 326, the UMS160 can release the call established between the calling party and thecalled party in step 328. If on the other hand, the called party numberis busy, the UMS 160 can provide the calling party other options (e.g.,send email), or can end the call as requested by the calling party.Interactions between the calling party and the UMS 160 can be conductedby an interactive voice response system of the VM 190 that processesvoice responses of the calling party and/or DTMF selections.

Referring back to step 318, if the UMS 160 has for example multipleoutdial alternatives (e.g., a home number and an office number of thecalled party), the UMS can proceed to step 324 where it conveys music onhold to the calling party while it attempts the alternate numbers toreach the called party. If the called party answers the call in step326, then the UMS 160 remove the music on hold status and releases thecall in step 328 as previously described. If the called party does notanswer in step 326 the first number dialed by the CCS 180 or the numberis busy, the UMS 160 can transmit to the CCS in step 324 a newdestination number to attempt. Since the CCS 180 has been directed instep 310 to provide outdial event notification, the UMS 160 does notneed to resubmit a SIP SUBSCRIBE message to request the eventnotification service. Additionally, since the CCS 180 already has thecalling card information of the calling party, this information does nothave to be resubmitted by the UMS 160 as in step 312.

If the called party answers the alternate number in step 326, the UMS160 releases the call in step 328. If the alternate number is busy, theUMS 160 can provide alternate communication options (e.g., email,paging, instant messaging, etc.), or can end the call as directed by thecalling party.

Method 300 thus provides the UMS 160 a means to make informed decisionsas to how to process signaling information received from the calledparty

Upon reviewing the embodiments disclosed, it would be evident to anartisan with ordinary skill in the art that said embodiments can bemodified, reduced, or enhanced without departing from the scope andspirit of the claims described below. For example, method 300 can beapplied to a plurality of intermediate systems or IVRs such as CCS 180.Accordingly, SIP SUBSCRIBE messages including a request for outdialevents can be submitted to a sequence of intermediate nodes of thecommunication system 100 to monitor the status of signaling informationreceived by these intermediate nodes based on SIP NOTIFY messagessupplied by said nodes.

Other suitable modifications can be applied to the present disclosurewithout departing from the scope of the claims below. Accordingly, thereader is directed to the claims for a fuller understanding of thebreadth and scope of the present disclosure.

FIG. 5 depicts an exemplary diagrammatic representation of a machine inthe form of a computer system 500 within which a set of instructions,when executed, may cause the machine to perform any one or more of themethodologies discussed above. In some embodiments, the machine operatesas a standalone device. In some embodiments, the machine may beconnected (e.g., using a network) to other machines. In a networkeddeployment, the machine may operate in the capacity of a server or aclient user machine in server-client user network environment, or as apeer machine in a peer-to-peer (or distributed) network environment.

The machine may comprise a server computer, a client user computer, apersonal computer (PC), a tablet PC, a laptop computer, a desktopcomputer, a control system, a network router, switch or bridge, or anymachine capable of executing a set of instructions (sequential orotherwise) that specify actions to be taken by that machine. It will beunderstood that a device of the present disclosure includes broadly anyelectronic device that provides voice, video or data communication.Further, while a single machine is illustrated, the term “machine” shallalso be taken to include any collection of machines that individually orjointly execute a set (or multiple sets) of instructions to perform anyone or more of the methodologies discussed herein.

The computer system 500 may include a processor 502 (e.g., a centralprocessing unit (CPU), a graphics processing unit (GPU, or both), a mainmemory 504 and a static memory 506, which communicate with each othervia a bus 508. The computer system 500 may further include a videodisplay unit 510 (e.g., a liquid crystal display (LCD), a flat panel, asolid state display, or a cathode ray tube (CRT)). The computer system500 may include an input device 512 (e.g., a keyboard), a cursor controldevice 514 (e.g., a mouse), a disk drive unit 516, a signal generationdevice 518 (e.g., a speaker or remote control) and a network interfacedevice 520.

The disk drive unit 516 may include a machine-readable medium 522 onwhich is stored one or more sets of instructions (e.g., software 524)embodying any one or more of the methodologies or functions describedherein, including those methods illustrated above. The instructions 524may also reside, completely or at least partially, within the mainmemory 504, the static memory 506, and/or within the processor 502during execution thereof by the computer system 500. The main memory 504and the processor 502 also may constitute machine-readable media.

Dedicated hardware implementations including, but not limited to,application specific integrated circuits, programmable logic arrays andother hardware devices can likewise be constructed to implement themethods described herein. Applications that may include the apparatusand systems of various embodiments broadly include a variety ofelectronic and computer systems. Some embodiments implement functions intwo or more specific interconnected hardware modules or devices withrelated control and data signals communicated between and through themodules, or as portions of an application-specific integrated circuit.Thus, the example system is applicable to software, firmware, andhardware implementations.

In accordance with various embodiments of the present disclosure, themethods described herein are intended for operation as software programsrunning on a computer processor. Furthermore, software implementationscan include, but not limited to, distributed processing orcomponent/object distributed processing, parallel processing, or virtualmachine processing can also be constructed to implement the methodsdescribed herein.

The present disclosure contemplates a machine readable medium containinginstructions 524, or that which receives and executes instructions 524from a propagated signal so that a device connected to a networkenvironment 526 can send or receive voice, video or data, and tocommunicate over the network 526 using the instructions 524. Theinstructions 524 may further be transmitted or received over a network526 via the network interface device 520.

While the machine-readable medium 522 is shown in an example embodimentto be a single medium, the term “machine-readable medium” should betaken to include a single medium or multiple media (e.g., a centralizedor distributed database, and/or associated caches and servers) thatstore the one or more sets of instructions. The term “machine-readablemedium” shall also be taken to include any medium that is capable ofstoring, encoding or carrying a set of instructions for execution by themachine and that cause the machine to perform any one or more of themethodologies of the present disclosure.

The term “machine-readable medium” shall accordingly be taken toinclude, but not be limited to: solid-state memories such as a memorycard or other package that houses one or more read-only (non-volatile)memories, random access memories, or other re-writable (volatile)memories; magneto-optical or optical medium such as a disk or tape; andcarrier wave signals such as a signal embodying computer instructions ina transmission medium; and/or a digital file attachment to e-mail orother self-contained information archive or set of archives isconsidered a distribution medium equivalent to a tangible storagemedium. Accordingly, the disclosure is considered to include any one ormore of a machine-readable medium or a distribution medium, as listedherein and including art-recognized equivalents and successor media, inwhich the software implementations herein are stored.

Although the present specification describes components and functionsimplemented in the embodiments with reference to particular standardsand protocols, the disclosure is not limited to such standards andprotocols. Each of the standards for Internet and other packet switchednetwork transmission (e.g., TCP/IP, UDP/IP, HTML, HTTP) representexamples of the state of the art. Such standards are periodicallysuperseded by faster or more efficient equivalents having essentiallythe same functions. Accordingly, replacement standards and protocolshaving the same functions are considered equivalents.

The illustrations of embodiments described herein are intended toprovide a general understanding of the structure of various embodiments,and they are not intended to serve as a complete description of all theelements and features of apparatus and systems that might make use ofthe structures described herein. Many other embodiments will be apparentto those of skill in the art upon reviewing the above description. Otherembodiments may be utilized and derived therefrom, such that structuraland logical substitutions and changes may be made without departing fromthe scope of this disclosure. Figures are also merely representationaland may not be drawn to scale. Certain proportions thereof may beexaggerated, while others may be minimized. Accordingly, thespecification and drawings are to be regarded in an illustrative ratherthan a restrictive sense.

Such embodiments of the inventive subject matter may be referred toherein, individually and/or collectively, by the term “invention” merelyfor convenience and without intending to voluntarily limit the scope ofthis application to any single invention or inventive concept if morethan one is in fact disclosed. Thus, although specific embodiments havebeen illustrated and described herein, it should be appreciated that anyarrangement calculated to achieve the same purpose may be substitutedfor the specific embodiments shown. This disclosure is intended to coverany and all adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the above description.

The Abstract of the Disclosure is provided to comply with 37 C.F.R.§1.72(b), requiring an abstract that will allow the reader to quicklyascertain the nature of the technical disclosure. It is submitted withthe understanding that it will not be used to interpret or limit thescope or meaning of the claims. In addition, in the foregoing DetailedDescription, it can be seen that various features are grouped togetherin a single embodiment for the purpose of streamlining the disclosure.This method of disclosure is not to be interpreted as reflecting anintention that the claimed embodiments require more features than areexpressly recited in each claim. Rather, as the following claimsreflect, inventive subject matter lies in less than all features of asingle disclosed embodiment. Thus the following claims are herebyincorporated into the Detailed Description, with each claim standing onits own as a separately claimed subject matter.

What is claimed is:
 1. A non-transitory machine-readable storage medium,comprising executable instructions which, responsive to being executedby a processor, cause the processor to facilitate performance ofoperations comprising: receiving from a unified messaging system asession initiation protocol subscribe message over a primary call legrequesting outdial event notification on a secondary call leg responsiveto the unified messaging system placing a call outside of its localaccess and transport area, wherein the unified messaging system operatesin an Internet protocol multimedia subsystem network, and wherein theprimary and the secondary call legs bypass the Internet protocolmultimedia subsystem network; placing a call on the secondary call legresponsive to receiving, on the primary call leg, outdial informationfrom the unified messaging system, wherein receiving the outdialinformation is responsive to an autodial request to a voicemail messageof the unified messaging system, and wherein the outdial information isdirected towards a calling party of the voicemail message; submitting asession initiation protocol notify message to the unified messagingsystem that indicates outdial events associated with call status of thecall on the secondary call leg; and responsive to the call on thesecondary leg being unanswered: receiving alternative outdialinformation directed to the calling party of the voicemail message; andplacing another call on the secondary leg responsive to receiving thealternative outdial information, wherein the placing of the other calldoes not require receiving from a unified messaging system anothersession initiation protocol subscribe message over the primary call legrequesting outdial event notification on the secondary call leg.
 2. Thenon-transitory machine-readable storage medium of claim 1, wherein theoutdial information comprises one among an E.164 telephone number and auniform resource indicator.
 3. The non-transitory machine-readablestorage medium of claim 1, wherein the outdial event comprises one of asession initiation protocol provisional response, a session initiationprotocol final response or a combination thereof.
 4. The non-transitorymachine-readable storage medium of claim 3, wherein the sessioninitiation protocol provisional and final responses are defined by theInternet Engineering Task Force in request for comments
 3261. 5. Thenon-transitory machine-readable storage medium of claim 1, wherein acalling card server performs session initiation protocol messaging. 6.The non-transitory machine-readable storage medium of claim 1, wherein acalling card server corresponds to an interactive voice response system.7. The non-transitory machine-readable storage medium of claim 1,wherein the call is placed on a voice over Internet protocol networkthat produces the outdial events.
 8. The non-transitory machine-readablestorage medium of claim 1, wherein the outdial information is responsiveto presence information of the calling party of the voicemail message.9. A unified messaging system, comprising: a memory that storesexecutable instructions; and a processor coupled to the memory, whereinthe processor, responsive to executing the instructions, facilitatesperformance of operations comprising: submitting to a calling cardserver over a primary call leg a session initiation protocol subscribemessage requesting outdial event notification for a call on a secondarycall leg responsive to an autodial request to a caller identificationassociated with a calling party of a voicemail message of the unifiedmessaging system, and wherein the call on the secondary call leg isdirected to said caller identification, wherein the unified messagingsystem operates in an Internet protocol multimedia subsystem network,and wherein the primary and the secondary call legs bypass the Internetprotocol multimedia subsystem network; receiving over the primary callleg a session initiation protocol notify message from the calling cardserver indicating outdial events associated with placing the call overthe secondary call leg; and responsive to the call on the secondary legdirected to said caller identification being unanswered: determining analternative destination number of the calling party of the voicemailmessage; and initiating another call on the secondary leg responsive toalternative destination number, wherein the initiating of the other calldoes not require receiving from a unified messaging system anothersession initiation protocol subscribe message over the primary call legrequesting outdial event notification on the secondary leg.
 10. Theunified messaging system of claim 9, wherein the operations furthercomprise: submitting to the calling card server a session initiationprotocol invite message with outdial information to place the call overthe secondary call leg; and receiving session initiation protocol notifymessages from the calling card server regarding call status associatedwith placing the call over the secondary call leg.
 11. The unifiedmessaging system of claim 10, wherein the outdial information comprisesone among an E.164 telephone number and a uniform resource indicator.12. The unified messaging system of claim 9, wherein the calling cardserver is communicatively coupled to a public switched telephonenetwork.
 13. The unified messaging system of claim 9, wherein theoperations further comprise: submitting a session initiation protocolinvite message to establish communications with the calling card serverover the primary call leg; and transmitting, to the calling card server,dual tone multi-frequency signals corresponding to a calling card numberand destination number to direct the calling card server to place thecall over the secondary leg.
 14. The unified messaging system of claim9, wherein the outdial event comprises one of a session initiationprotocol provisional response, a session initiation protocol finalresponse or a combination thereof.
 15. The unified messaging system ofclaim 9, wherein the operations further comprise: transmitting thesession initiation protocol subscribe message to the calling card serverresponsive to a subscriber of the unified messaging system replying to avoicemail message; identifying a party leaving the voicemail message;and determining a telephone number to reach the party from presenceinformation associated with the party.
 16. The unified messaging systemof claim 9, wherein the operations further comprise contacting thecalling card server when placing a call outside of its local access andtransport area.
 17. The unified messaging system of claim 9, wherein theoperations further comprise obtaining the caller identification from apresence server.
 18. A calling card system, comprising: a memory thatstores executable instructions; and a processor coupled to the memory,wherein the processor, responsive to executing the instructions,facilitates performance of operations comprising: transmitting a sessioninitiation protocol notify message to a unified messaging system over aprimary call leg, wherein the session initiation protocol notify messageincludes call status associated with a secondary call leg, wherein theunified messaging system operates in an Internet protocol multimediasubsystem network, and wherein the primary and the secondary call legsbypass the Internet protocol multimedia subsystem network; andinitiating a call on the secondary call leg responsive to an autodialrequest to a caller identification of a calling party of voicemailmessage received from the unified messaging system in response to thevoicemail message presented by the unified messaging system; andresponsive to the call on the secondary leg being unanswered:determining another autodial request to an alternative destinationnumber of the calling party of the voicemail message; and initiatinganother call on the secondary leg responsive to the alternativedestination number, wherein the initiating of the other call does notrequire receiving from a unified messaging system another sessioninitiation protocol subscribe message over the primary call legrequesting outdial event notification on the secondary leg.
 19. Thecalling card system of claim 18, wherein the operations further comprisereceiving a session initiation protocol subscribe message requesting thecall status on the secondary call leg.
 20. The calling card serversystem of claim 19, wherein the operations further comprise receiving,from the unified messaging system, outdial information associated withthe voicemail message that includes a calling card number and one amongan E.164 telephone number and a uniform resource indicator.
 21. Thecalling card system of claim 18, wherein the operations further comprisebeing contacted by the unified messaging system when the unifiedmessaging system places a call outside of its local access and transportarea.
 22. The calling card system of claim 18, wherein the operationsfurther comprise establishing communications over the secondary call legwith a called endpoint comprising one among a voice over Internetprotocol client and a public switched telephone network client.
 23. Thecalling card server system of claim 18, wherein the call statuscomprises one of a session initiation protocol provisional response, asession initiation protocol final response or a combination thereof. 24.The calling card system of claim 18, wherein the operations furthercomprise receiving a call back number of a calling party of thevoicemail message, the call back number responsive to presenceinformation of the calling party.